When conduits, whether they are constituted as pipes, hoses, electrical wires, or the like, pass through a wall it is normally necessary to seal tightly and hermetically around them. In particular in firecode construction it is necessary for the joint around the conduits to be of the same rating as the wall. Accordingly it is known to use wall feedthrough fittings comprising basically a sleeve that is fitted through the wall and through which the conduits pass longitudinally and a group of blocks that fit snugly between the conduits and the sleeve.
According to German patent 958,671 the blocks are generally parallepipedal and a plurality is used so that the joints or interface surfaces between adjacent blocks normally run both vertically and horizontally. These interface surfaces are, of course, formed with cutouts that together snugly embrace the conduits which are typically of circular section. The entire group of blocks is pressed tightly together by a plate that bears against all of them along one edge of the normally square sleeve and that can be pressed by bolts against these blocks. Once this plate is pushed in place to compress the blocks, the space it opens up must itself be plugged by other blocks.
In order to prevent extruding the blocks out of the opening, the plate is shaped complementarily to them and arranged flatly parallel on them. In addition between adjacent rows of such blocks there are stiffening plates with edges that hang over the ends of the blocks and that further inhibit their longitudinal movement when compressed. The blocks bear directly against the edges of the stiffening plates which are formed on the opposite sides with concave recesses so that the elastic blocks fill these recesses and thereby seal with the stiffening plates.
Such a system requires the use of relatively large compression forces to ensure a good seal. Unfortunately such pressure can damage some conduits, for instance electrical or fiber-optic cables. In addition this system is quite complicated and, therefore, expensive. It is also necessary for the installer stock a large supply of differently dimensioned blocks for the different conduits and sleeves. The provision of the stiffening plates further limits the placement of the conduits and often requires that the sleeve be much larger than would otherwise be necessary. Finally the prior-art system is almost impossible to rebuild once it is installed, as the blocks cannot be removed conveniently.